Ferrotitanium alloy



Paiented June 23, I942 FERROTITANIUM ALLOY Jerome Strauss, New York, N.Y., and Holbert Earl Dunn, Bridgeville, Pa", assignors to VanadiumCorporation of America, New York, N. Y., a corporation of Delaware NoDrawing.

Application February 15, 1940,

Serial No. 319,080 s Claims. (01. 75-58) This invention relates toferro-titanium alloys useful as-addition agents for iron and steel. Itrelates more particularly to ferro-titanium alloys containing asubstantial amount of manganese. The presence of manganese insubstantial amount in these ferro-titanium alloys results in densebrilliant alloys free from slag inclusions, oxide and nitride products.The alloy'containing a substantial amount of manganese appears to rendereasier the removal of the products of deoxidation of the steel or ofother non-metallic particles with which these deoxidatlon products mayassociate themselves.- The resultant steel is,'therefore, cleaner andthere is less likelihood of defective articles resulting from thepresence of non-metallic particles during hot or cold working ormachining; that would be disadvantageous either to the mechanicalproperties or to the surface appearance of the finished articles; I

The present application is a continuation-inpart of application SerialNo. 306,179, filed November 25, 1939, which in turn is acontinuationin-part of application Serial No. 114,830, filed December 8,1936. Ferro-titanium alloys according to the present invention may be ofthe low, medium or high carbon types. Ferro-titanium alloys containingunder .5% carbon are generally classified as low carbon term-titanium,those containing from .5 to carbon as medium carbon term-titanium, andthose containing over 5% carbon as high carbon ferro-titanium. In ouralloy, the carbon is less than and preferably is between .05 and 8%. Thetitanium may be as low as 10% or as high as 50% by weight of the alloybut is preferably between about and 45% or more particularly betweenabout 15 and 30%. The alloy also contains manganese in' substantialamount or both manganese in substantial amount and silicon. Themanganese amounts to about 2 to 15% of our alloy, the preferred rangebeing from about 3 to 10% or more; particularly from about 4 to 7%.

Our alloy may or may not contain substantial amounts of silicon oraluminum or both sllicon and aluminum in addition to the iron, carbon,titanium andmanganese. Where silicon' is present in the alloy. it mayamount to about .05 to 30% or preferably from about 1 to 15%. In themanufacture of low, medium and high carbon ferro-titanium alloys,silicon often is present in amounts ranging from less than 1% up toabout 4%, depending upon the starting materials and the particularmethod employed. In the 55 manufacture of low and medium carbonferrotitanium alloys, silicon is sometimes present in amounts betweenabout 10 and 20%. Similarly some aluminum is always present inferro-titanium alloys. Medium and high carbon ferro-titanium alloys maycontain aluminum in amounts from a trace up to about 3%, depending uponthe nature of the raw materials which are employed. Low carbonferro-titanium alloys produced by methods using aluminum as the reducingagent may contain up to about 10% of aluminum. Our invention coversferro-titanium alloys in which there is a substantial amount ofmanganese and in which silicon or aluminum or both may or may not bepresent. The silicon in our alloy may be up to about 30% and thealuminum may be up to about 10% Our alloy containing manganese withinthe ranges specified is advantageous over the prior known ferrotitaniumalloys whether or not our alloy contains a substantial amount, ofsilicon. For certain purposes, the presence of substantial amounts ofsilicon or aluminum or both silicon and aluminium content may beemployed in the alloy, substantial amounts of manganese imparts furtheradvantageous properties to the alloy. Our ferro-titanium alloy alwayscontains at least 20% of iron, and in the preferred compositionscontains at least 40 or 50% of iron.

We have discovered that part of the titanium content of theferro-titarn'um may be effectively replaced by zirconium. The amount ofzirconium should not in any case be greater than 50% of the titaniumplus zirconium content. In other words, the amount of zirconium shouldnot exceed the amount of titanium. Any amount of zirconium up to anamount equal to the titanium content may be employed in the alloy,although we prefer that the zirconium be from 15 to 50% of the titanium.A very useful alloy,

for example, contained:

Per cent C 4.0 Si 3.5 Mn 6.5 17.5 Zr 5.0

Balance substantially all iron We have used with greatest success alloysin which the manganese was in the range of about 10 to40% of the contentof titanium where the alloy does not contain an appreciable amount ofzirconium, or a range of about 10 to 40% of the content of titanium pluszirconium where the alloy contains an appreciable amount of zirconium,regardless of whether the manganese was employed alone or together withsilicon.

We have found that the addition to steels or irons of a ferro-titaniumalloy containing manganese or both manganese and silicon within theranges specified produces effects in respect to cleanliness, soundnessand uniform crystallization in the irons and steels which are markedlydifferent from those obtained when the ferroalloys of these elements areused independently. In other words, the use of this ferro-titanium alloycontaining manganese or both manganese and silicon, either with orwithout zirconium present, produces results in steel deoxidation andcleanliness that are not obtainable by the addition of the separateferro-alloys when added to steel either simultaneously or successively.In fact, steels treated with the alloys of this invention are found tobe freer from nitrogen containing inclusions that so frequently occur insteels to which have been added the titanium or zirconium alloysheretofore known.

A major field of application of ferro-titanium alloys according to thepresent invention, especially the medium carbon ferro-titanium alloyscontaining from .5 to 5% carbon, is in de oxidizing the so-called rimmedsteels which require an ingot surface of the highest attainable quality.For this purpose, it is customary to treat the liquid steel in the ladlewith from 1 to 3 pounds of ferro-titanium per ton or 0.01% to 0.03%titanium in the steel were the titanium recovered 100%. As a matter offact, only traces of titanium can usually be found residual in thesolidified steel, the bulk of the addition having reacted with and beenslagged oil with the ferrous oxide, manganese oxide, nitrides and silicaparticles entrained or dissolved in or precipitated during cooling fromthe molten metal. If for example, 3 pounds of ferro-titanium alloy areadded per ton of steel, the alloy having an analysis of 20% titanium, 6%manganese, 3% silicon and 4% carbon, and these elements are recovered100%, the analysis of the steel would be changed to the extent of 0.03%titanium, 0.009% manganese, 0.005% silicon and 0.006% carbon. When sheetand tin bar are being produced at 0.05% to 0.08% carbon, the possibilityof carbon, manganese and silicon pick-up caused by deoxidizer additionsis of importance. As a matter of fact, this pick-up is rarely observedwithin the range of ordinary analytical methods, as part of thesereducing agents are oxidized by the ferrous and other oxide content ofthe molten steel and slagged off, while the amounts remaining are lessthan the sensitivity of the analytical methods.

In the high carbon or killed'? steels, where high-carbon ormedium-carbon ferro titaniinh additions as high as 18 pounds per tonhave been made, the analysis of the steel, in case 100% recovery of thealloying elements addedin the ferro-titanium deoxidizer could beeffected, would only be changed to the extent of 0.12% titanium,

0.05% manganese, 0.03% silicon, and 0.036% carferro-titanium alloys,particularly those containing a medium carbon content.

The invention is not limited to the preferred embodiments but may beotherwise embodied or practiced within the scope of the followingclaims.

We claim:

1. A ferro-titanium alloy containing less than 10% carbon, an effectiveamount of titanium, an eiiective amount of zirconium, the sum of thetitanium and zirconium being between about 10 and the zirconium notexceeding the titanium, about 2 to 15% of manganese, the balance beingsubstantially all iron except for silicon in amount from about .05 to30% and aluminum in amount from a trace up to about 10%.

2. A term-titanium alloycontaining less than 10% carbon, an efiectiveamount of titanium, an eiiective amount of zirconium, the sum of thetitanium and zirconium being between about 10 and 50%, the zirconium notexceeding the titanium, about 3 to 10% .of manganese, the balance beingsubstantially all iron except for silicon in amount from about .05 to30% and aluminum in amount from a trace up to about 10%.

3. A ferro-titanium alloy containing less than 10% carbon, an effectiveamount of titanium, an effective amount of zirconium, the sum of thetitanium and zirconium being between about 10 and 50%, the zirconiumbeing about 15 to 50% of the titanium, about 2 to 15% of manganese, thebalance being substantially all iron except for silicon in amount fromabout .05 to 30% and aluminum in amount from a trace up to about 10%.

JEROME STRAUSS.

HOLBERT EARL DUNN.

CERTIFICATE OF commcnon. Patent No. 2,287,712. June 2 1942.

saorm: swm'uss, ET'AL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 1,sec- 0nd column, lines 25-end 2l|. for "alnminiu m content may beem-ployedinthe elloy," read --a1mninum in ox'ir ferro-titanium alloyscontaining--; and that the said Letters Patent should be read with thiscorrection therein' that the seLme may conform to the record of the casein the Patent Office.

Signed and sealed this 14th day of August, A- D- 9 4 Henry Van Arsdale,I (Seal) Acting Counnissioner of Patents.

